Aircraft power systems in various types of aircraft frequently provide differing types of supply voltages. Occasionally, power supplies on the aircraft may be required to convert power from these different types of supply voltages into a higher voltage DC source. For example, a single avionics power supply may be required to draw power from an AC source or a DC source as provided by an aircraft power system. More specifically, the AC power source may require the load (avionics power supply) to be corrected for power factor and current harmonics, or that the rectified equivalent of the AC supply be stepped up to a higher voltage to provide extended playthru of power interrupts. In this given scenario, a preconvertor is typically required at the AC input to the power supply. Power drawn from a DC source, typically 12 to 40V, may be required to be stepped up by a preconvertor to some higher voltage to provide playthru for DC power interrupts. In either case, an additional convertor is required to condition the incoming power supply to that which is usable by a specific load. The burden becomes truly great when the same power supply is required to draw its power from both AC and DC type sources in this fashion.
The need for separate convertors necessary in the prior art for preconverting or conditioning AC and DC inputs requires significantly more space in the avionics than is desired. In avionics systems, available space is typically at a minimum. Additionally, the separate convertors necessary for preconverting or conditioning the AC and DC inputs requires additional components which increases costs. Specifically, each of the two conversion circuits or stages typically requires its own transformer, which affects cost and space adversely.